More precisely, the present invention concerns a traffic information system comprising:                at least a mobile device having a localization function adapted to determine a current location thereof, said mobile device being adapted at least to display a navigation route,        a host server connected to Internet,        at least a traffic information server, connected to Internet, adapted to provide updated standard traffic information files, said updated standard traffic information files comprising traffic information relative to a large territory,        a communication channel between the mobile device and the host server, including a wireless portion,        
wherein the mobile device transmits said current location to the host server at least from time to time,
wherein the host server is adapted to get updated standard traffic information files from the traffic information server.
Such a traffic information system is known from document US2007/0219715. However, there is a need to further optimize said communication channel, knowing the data rate limitations on the wireless interface, and the costs of communications on this communication channel.